Need more info, does it click on and off, make any noises, was the picture going blurry, did you just move it, was in built into a wall where it wouldn't get air to cool???
Here is what I know about the 51mp392h this is a general post below I used for some other peoples fixes without more info on yours I suggest reading thru the below and links and add more info to your post so we can trouble shoot it.
Actually I have this TV and you need 2 Convergence IC's STK392-120's (120's and 150's will work) of course order 2 of the same type I'm using replacement 150's they allow for a little higher heat and were cheaper ALSO you need to replace the 12 resistors with 6.8 ohm metal film resistors, make sure they are metal film! don’t skimp out here I did and then they blew and fried my IC's and I had to replace everything again!
Great reference link that I posted pictures on, check out page 3
Where I got all my parts that worked:
Suburban Electronics http://www.suburban-elect.com/
you should find all you need here:
What you need:
(2) STK392-120 OR STK392-150 IC chips
(12) 6.8 Ohm Metal Film resistors
set of star screw drivers
15 watt pencil solder pencil, DO NOT use a high watt iron you will fry the surface mounted item.
good leaded solder, and flux
BTW if you don’t plan on trying this and are going to throw out the TV, I still need a IC convergence board for a 51MP392H/17 TV I'm fixing, I'm willing to pay S/H and buy your IC board that’s not been tampered with. Edwinkraus@hotmail.com